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Biomedical subjects

D Roberts

Publications and source records attributed to D Roberts.

At least 127 records · Page 7Linked to original sources
PubMed1997

Neonatal exposure to coumestrol, a phytoestrogen, does not alter spermatogenic potential in rats.

The objective of this study was to determine the effects of neonatal exposure to phytoestrogens on male reproductive function as adults. Male rats were injected either with 100 micrograms coumestrol or DMSO (controls) daily during their first 5 d of life. Pituitary gland, testes, sex accessory organs, and blood were collected on d 60 of life. Serum testosterone, LH, and FSH levels were determined by RIA. Levels of steady-state mRNA for gonadotrophin subunits (LH beta and FSH beta were determined by Northern blot analysis and quantified by a scanning densitometer. Coumestrol had no effect on weights of testes and sex accessory organs, or sperm count. Similarly, there were no significant differences among serum concentrations of testosterone, LH beta and FSH of coumestrol-treated rats and those of controls. Whereas steady state levels of LH beta mRNA in coumestrol-treated rats did not differ from those of controls, steady state levels of FSH beta mRNA increased (37%) in treated animals. However, the augmented FSH beta mRNA expression in coumestrol-treated rats did not negatively affect reproductive potential in male rats. We conclude that neonatal exposure to coumestrol does not alter reproductive organ structure or spermatogenic potential in male rats.

Animals↗
PubMed1997

Transesophageal echocardiographic detection of complications after Cabrol's procedure.

Cabrol's procedure represents an improvement on earlier surgical techniques used in the management of a patient with aortic insufficiency associated with an aneurysm of the ascending aorta. We report a patient in whom the diagnosis of complications after a Cabrol procedure was facilitated by transesophageal echocardiography. The role of transesophageal echocardiography in the follow-up of these patients is discussed.

Abscess↗
PubMed1997

Liaison mental health nursing: origins, definition and prospects.

Liaison mental health nursing is an evolving specialist area of mental health nursing in the United Kingdom (UK). It has many similarities with 'psychiatric consultation liaison nursing' practised in the United States of America (USA), but there have been differences in its development. It is well established in general health settings where psychological problems are most apparent, such as accident and emergency services and oncology. However, it lacks clear definition. The author addresses this by examining the literature for evidence of how the role has developed, and how it is currently described. The position of liaison mental health practice within nursing is discussed, and also its relationship to liaison psychiatry. The theoretical base of this specialty may be seen as an integration of biological, psychological and sociological perspectives. There is no current programme of training for liaison mental health nurses, and this is likely to inhibit its recognition as a specialty in the UK. As interest grows in psychosocial aspects of physical health, liaison mental health nursing has the potential to provide a focus for research within nursing. Areas for further development are reviewed, and a research agenda is proposed.

Consultants↗
PubMed1997

Enzyme exposure, smoking and lung function in employees in the detergent industry over 20 years. Medical Subcommittee of the UK Soap and Detergent Industry Association.

This study was undertaken to examine the long term relationship between lung function, smoking and exposure to enzymes in the detergent industry. A total of 731 male workers from five locations in the United Kingdom were subject to respiratory health surveillance including lung function testing over a period of 4-20 years. Exposure groups were defined by job history. Significantly different rates of fall in FEV1 and FVC with time were found by geographical location and by smoking habit, but there were no consistent trends with enzyme exposure.

Adult↗
PubMed1997

Effect of inspiratory flow rate on respiratory rate in intubated ventilated patients.

It has previously been demonstrated that in normal subjects using a volume-cycled ventilator, increasing inspiratory flow rate increases respiratory rate. We undertook the current study to determine (1) whether this effect is also present in patients with respiratory disease and (2) whether the effect is independent of upper airway receptors. Eight ventilator-dependent patients in the intensive care unit were studied. Patients were ventilated in the assist-control mode with the back-up rate set at 0.5 breaths/min to ensure that all breaths were patient-triggered. While tidal volume was held constant, flow was changed from a baseline flow of 60 L/min. Trials involved changing flow to either 30 or 90 L/min. There was a significant decrease in respiratory rate (-3.4 +/- 0.6 min-1, p < 0.001) when flow was decreased from 60 to 30 L/min. There was a significant increase in respiratory rate (2.3 +/- 0.8 min-1, p < 0.05) when flow was increased from 60 to 90 L/min. As a result of the change in respiratory rate, TE (expiratory time) showed a variable response to changes in flow rate, with some patients actually demonstrating a reduced TE with higher flow rates. No patients experienced the increase in TE that would have been predicted without a change in respiratory rate. We conclude that in intubated ventilated patients, spontaneous respiratory rate is sensitive to inspiratory flow rate. This effect appears to be independent of upper airway receptors, since it was observed with a by-passed upper airway. The increase in respiratory rate seen at higher flow rates undermines attempts to increase TE by increasing flow rates. It may also cause a tendency toward respiratory alkalosis.

Adolescent↗
PubMed1997

Informing prescribing allocations at district level in England.

OBJECTIVES: To derive a predictive model based on the morbidity, demographic and socio-economic characteristics of district populations to explain variations in prescribing costs in England. METHOD: Inter-relations between morbidity, demographic, socio-economic, general practice supply characteristics and net ingredient cost per age, sex and temporary resident originated prescribing unit (ASTRO-PU) were explored statistically for 90 districts in England using 1994 cost data. The possibility of mutual inter-relationship between 'supply' and 'demand' was examined; then the associations between a range of factors and prescribing costs were estimated using ordinary least squares regression and the predictive power of the possible models was systematically examined. RESULTS: Whilst there was a relatively weak relationship between the supply factors that were measured, there did not appear to be any reciprocal relationship. Three parsimonious models estimated using ordinary least squares multiple regression techniques based on combinations of permanent sickness, low birth weight and the proportion of general practitioners registered for postgraduate certificate of education were identified. The models explained up to 61% of variation between districts in prescribing costs. CONCLUSIONS: 'Need' and 'supply' characteristics are independently associated with variations in prescribing costs at district level. The negative association between the proportion of general practitioners eligible for postgraduate education allowance and prescribing costs may reflect 'better' prescribing but could not be introduced into a resource allocation formula without introducing perverse incentives. The combination of permanent sickness and low birth weight complement each other by providing a proxy measure of morbidity mostly applicable to adult males (permanent sickness) and mothers (low birth weight being a measure of maternal health). These variables should be considered further for use in the process of allocating resources for prescribing to districts.

Cost Allocation↗
PubMed1997

Alfentanil mediated activation of epileptiform activity in the electrocorticogram during resection of epileptogenic foci.

PURPOSE: Alfentanil is a potent, short-acting opioid agent which has been used during balanced anaesthesia in children undergoing the surgical excision of epileptic foci. After the observation that this agent had the potential to induce epileptic seizures, we questioned the frequency of this occurrence in this group of patients. METHOD: Twelve patients (6 males, 6 females) undergoing surgical excision of an epileptic foci were prospectively followed. For each patient an electrocorticogram was recorded for 30 minutes before and after receiving alfentanil 20 micrograms/kg intravenously. The frequency of epileptiform abnormalities before and after drug administration was evaluated. When the electrocorticogram no longer showed the effects of alfentanil administration, methohexital 0.5 microgram/kg was given intravenously. RESULTS: Alfentanil induced significant activation of epileptiform discharges among 83% of these patients. Twenty-five per cent had an electrographic seizure. In comparison, methohexital induced significant activation of epileptiform discharges in 50% of these patients. None experienced electrographic seizures. CONCLUSIONS: As alfentanil can induce electrographic seizures in patients known to have epilepsy, caution is advised in its use in this group of patients.

Adolescent↗
PubMed1996

International epidemiological and microbiological study of outbreak of Salmonella agona infection from a ready to eat savoury snack--I: England and Wales and the United States.

OBJECTIVES: To identify the source of an international outbreak of food poisoning due to Salmonella agona phage type 15 and to measure how long the underlying cause persisted. DESIGN: Case-control study of 16 primary household cases and 32 controls of similar age and dietary habit. Packets of the implicated foodstuff manufactured on a range of days were examined for salmonella. All isolates of the epidemic phage type were further characterised by pulsed field gel electrophoresis. RESULTS: 27 cases were identified, of which 26 were in children. The case-control study showed a strong association between infection with S agona phage type 15 and consumption of a peanut flavoured ready to eat kosher savoury snack imported from Israel. S agona phage type 15 was isolated from samples of this snack. The combined food sampling results from the United Kingdom, Canada, the United States, and Israel showed that contaminated snacks were manufactured on at least seven separate dates during a four month period between October 1994 and February 1995. Voluntary recalls of the product successfully interrupted transmission. CONCLUSIONS: Rapid international exchanges of information led to the identification of the source of a major outbreak of S agona in Israel and of associated cases in North America. The outbreak showed the value of the Salm-Net surveillance system and its links outside Europe, both for increasing case ascertainment and for improving the information on the duration of the fault at the manufacturing plant.

Case-Control Studies↗
PubMed1996

Epilim chrono: a multidose, crossover comparison of two formulations of valproate in healthy volunteers.

The pharmacokinetic properties and relative bioequivalence of two formulations of the antiepileptic Epilim were compared in a three-period, repeat dose, randomized crossover study in 18 male volunteers. A daily dose of 1000 mg of antiepileptic was given either as twice-daily enteric-coated sodium valproate tablets or as twice- or once-daily controlled release tablets (Epilim Chrono, sodium valproate/valproic acid mixture). All regimens were bioequivalent with respect to area under the curve and elimination half-life. The twice-daily controlled release formulation showed reduced mean peak plasma valproate levels and raised mean trough levels compared with the enteric coated tablets. The once-daily controlled release regimen gave reduced mean peak levels but similar mean trough levels to the twice-daily enteric-coated regimen. No major differences between regimens were observed in the time at which peak concentration was observed. Both formulations were well tolerated. The most frequently reported adverse event was mild diarrhoea (all on Chrono treatment) which is probably related to the lack of enteric coating on this formulation. The reduced mean peak-trough variation in plasma valproate levels observed with the twice-daily controlled release regimen is likely to reduce further the low incidence of concentration-related side-effects with sodium valproate and permit more reliable plasma level monitoring. This study also indicates that once-daily treatment with Epilim controlled release would be a suitable replacement for twice-daily dosing with either formulation. Once-daily treatment is likely to give considerable benefits both in convenience and in better patient compliance.

Adolescent↗